Doppler flow meter

Abstract

A catheter probe flow meter and method of determining the volume flow of a fluid through a conduit, at least one of the fluid and the conduit having energy-scattering interfaces. The method in one embodiment includes trasmitting at least two and receiving at least one or transmitting at least one and receiving at least two sound beams through the fluid, resolving the Doppler vectors into an average velocity vector for each transmitting/receiving combination, and resolving the resolved velocity vectors into their component parts.

We claim: 
     
       1. A catheter transducer probe comprising an elongate catheter housing having a bore therein;   first and second acoustical transducers which generate and receive respective beams of sound, said transducers being mounted in a mutual coaxial relationship to said housing;   electrical conductors extending through said bore and electrically connected to said transducers;   first and second sound directing means comprising shaped acoustical reflectors mounted to said housing and acoustically coupled to said first and second transducers, respectively, so as to direct said first and second beams outwardly from said housing at a predetermined angle with respect to each other such that the Doppler vectors of the reflected back portions of said sound beams are nonparallel.   
     
     
       2. A probe as claimed in claim 1 wherein said transducers are spaced apart and coaxially mounted about the longitudinal axis of the housing and said directing means are coaxially mounted therebetween. 
     
     
       3. A probe as claimed in claim 1 wherein said transducers are spaced apart and said reflectors shaped as two back-to-back conical frustrum portions joined at their enlarged bases. 
     
     
       4. A probe as claimed in claim 1 wherein said transducers are mounted in mutual, juxtaposed, electrically insulated relationship and said sound directing means are located outwardly thereof. 
     
     
       5. An acoustical transducer probe comprising: an elongate housing;   first and second acoustical transducers which generate and receive respective beams of sound, said transducers being mounted in a mutual coaxial relationship to said housing;   a bore in said housing;   electrical conductors extending through said bore and electrically connected to said transducers;   first and second sound directing means comprising shaped acoustical reflectors mounted to said housing and acoustically coupled to said first and second transducers, respectively, so as to direct said first and second beams from said housing at a predetermined angle with respect to each other such that the Doppler vectors of the reflected back portions of said sound beams are nonparallel.